[Thoracoscopy--the method of choice in the determination of a malignancy as the cause of pleural effusion of unknown etiology].

UNLABELLED After complete pulmological investigation remains about 20% of all the pleural effusions without etiological diagnosis designated as unexplained pleural effusions. Thoracoscopy enables further investigation with the final aim--establishing of the etiological cause of the unexplained pleural effusions. Recently numerous studies demonstrated that the malignancy is the most frequent cause of this aforementioned pleural effusions. OBJECTIVE Descriptive-analytic appraisal of validity of thoracoscopy in establishing of malignancy as a cause of idiopathic pleural effusions. TASKS: To establish if the malignancy is the most frequent cause of unexplained pleural effusions, to establish diagnostic-thoracoscopic sensitivity and specificity for malignant disease as cause of pleural effusions and to establish positive and negative predictive value of thoracoscopy for malignancy. PATIENTS AND METHODS In the period between 06.11.1984 and 01.02.2002, included in this investigation were all patients with pleural effusions of unknown origin who were referred to the Clinic for Thoracic Surgery--UCC Sarajevo, for thoracoscopy after less invasive means of diagnosis had failed. Investigation had clinical-manipulative, descriptive-analytic and retrospective-prospective design. RESULTS There were 74 patients with the pleural effusions of unknown origin. The malignancy was found in 47.3% (35/74) patients. Diagnostic sensitivity of the method for malignancy was 89.7% and the specificity 100.0%. The positive predictive value of the thoracoscopy for malignancy was 100.0% and negative predictive value 89.7%. CONCLUSIONS The malignancy was the most frequent cause of idiopathic pleural effusions. Thoracoscopy has high specificity and sensitivity in regard to discovering of malignancy as a cause of idiopathic pleural effusions. Undiagnosed malignancy by thoracoscopy excludes malignancy as a cause of pleural effusion with high security.